Optics

NuSTAR employs grazing incidence mirrors to focus the high-energy (3-79 keV)
radiation. Two Wolter-I design telescopes point at the same
portion of the sky, their images being added together on the ground.

Deployable Mast

NuSTAR is a Small Explorer mission and had to fit inside the Pegasus launch
vehicle: at launch, NuSTAR was no more than two meters long and one meter in
diameter. Therefore, to attain the required 10m focal length needed for its
telescopes, NuSTAR used a unique deployable mast, or boom, that extended the
optics after the payload was in orbit.

CdZnTe Detectors

NuSTAR has two detector units, each at the focus of one of the two co-aligned
NuSTAR optics units. The focal planes are each comprised of
four 32 x 32 pixel Cadmium-Zinc-Tellurium (CdZnTe, or CZT) detectors. These
are "state-of-the-art" room-temperature semiconductors which are very
efficient at turning high energy photons into electrons.